An online vibration monitoring system is a measurement system that automatically collects vibration data in a continuous fashion. When such a system is installed, the user configures the system for the type of data that is to be collected and under what conditions, and the system then runs automatically, without human intervention, 24/7, per its configuration. One example of this type of system is the CSI 6500 Machinery Health Monitor manufactured by Emerson Process Management.
Many online vibration monitoring systems, including the CSI 6500, use hardware integration to transform an acceleration signal into a velocity signal. Once the system is configured, a channel is either a velocity channel that uses a hardware integrator or an acceleration channel that bypasses the hardware integrator, until the system is reconfigured.
As the term is used herein, “Overall Vibration” is a measure of the total vibration amplitude over a wide range of frequencies. An Overall Vibration measurement, also referred to as a Gross Scan (GS) measurement, is a single broadband value that is relatively easy to collect, process, analyze and trend. The CSI 6500 is operable to measure Overall Vibration continuously and simultaneously on all channels once per second. The system can also be configured to additionally make a more detailed measurement on a pair of channels, which may be done on a periodic basis or triggered by the level of the Overall Vibration (and other inputs, such as Speed).
A significant limitation, however, is the restriction that a channel may be configured to measure either velocity or acceleration, but not both at the same time. A desired use case is to monitor velocity continuously and trending Overall Vibration in velocity (e.g., inches/second), but also to periodically make a more detailed acceleration measurement, such as a PeakVue measurement. This has not been possible with prior versions of the CSI 6500 unless two separate channels were used (one for velocity and one for acceleration). However, most users do not want to use two separate channels for this purpose, because twice as many channels are needed in the measurement system, which increases the cost.
What is needed, therefore, is a solution that eliminates this limitation in the prior art, preferably with no change to the measurement hardware.